In a country without a written constitution, British politicians struggle to contend with Twitter, Facebook and other social media at a time of crisis. David Cameron, in the aftermath of the riots, asked "whether it would be right" to ban people from using Facebook, Twitter or their BlackBerrys "when we know they are plotting violence, disorder and criminality". The backbench Conservative MP Louise Mensch went further, arguing that Twitter and Facebook should be taken down during "a major national emergency".

If the suggestions appear reasonable, remember that no politician would seek to switch off TV news or demand a newspaper blackout during a riot; even the decision to switch off mobile networks during the London 7/7 bombings to ensure the police could communicate more easily was subsequently recognised as an error by the then Metropolitan police commissioner, Sir Ian Blair.

Nor would the prime minister argue that people should be restricted in their right to communicate or consume media unless they were in prison.

Complicating the picture further are other reviews that Cameron has launched of media and communications policy, which seemingly support Twitter and other social media. In May, the prime minister was more exercised by the flouting of privacy injunctions on Twitter, saying that the law should be reviewed to "catch up with how people consume media today" because it was unfair that newspapers were unable to identify philandering celebrities such as Ryan Giggs, who had taken out an injunction, when their identity was freely circulating on Twitter.

That exercise is due to be conducted by a joint committee of MPs and Lords starting this autumn.

Separate from that, also, is the wide-ranging review to be led by Lord Justice Leveson, announced by Cameron in July, in response to the phone-hacking crisis. The judge and his team have been asked to look not just at the behaviour of the press but "other media organisations, including broadcasters and social media" and will make recommendations regarding "the extent to which the current policy and regulatory framework has failed" – leaving the way open for Leveson to propose new forms of regulation for social media as part of an exercise aimed at avoiding another scandal of the type that originated in the lightly regulated print media.

The result is an incoherent set of prime ministerial demands for more and less communication regulation, in effect calls for both more and less censorship at the same time.

Against that is set the position of three North American technology companies, coming from a continent with a clearly defined tradition of freedom of speech, as opposed to Britain's inherited European convention on human rights – which is hardly popular with the Conservatives, and whose balancing rights to privacy (article eight) and freedom of expression (article 10) still need to be considered in the context of each individual case.

Amid such confused thinking, it is hardly surprising that the Home Office was indicating yesterday that there would be no dramatic shift in government policy in the light of today's meeting between Theresa May, the home secretary, and representatives from Twitter, Facebook and Research in Motion, the BlackBerry maker.

It would be simpler, though, to assert clear freedom-of-speech and use principles to social media, coupled with a requirement to help the police in real time in situations of emergency, than to seek to artificially constrain technologies whose use is, in reality, beyond government control unless the most draconian measures are taken.